Process of making an insecticide and a fungicide



Patented June 1925.

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GEORG E .ETHELBERT SANDERS, 0F ANNAPOLIS ROYAL, NOVA SEOTIA, CANADA, AS-SIGNOR T0 RICHEE, PIVER & 00., A CORIURATION OF JERSEY.

PRQQES OIEMAIKI'NG AN I [NSECTICIDE AND A FUNGICIDE.

No Drawing.

The subject matter of this invention is a process of making a fungicideand an insecticide, either one or both combined or mixed, in the form ofa fine powder or dust,

according to the use to which it is to be put. In some cases-there is anadvantage in having both available for use and application to vegetationin one operation.

Copper forms the basis of an efi'ective.

fungicide and arsenic of an insecticide.

One of the features of this invention is in extracting the water ofcrystallization from copper sulphate crystals by chemical means toproduce a dehydrated copper sulphate which, when mixed with lime, formsa very effective fungicide in powder form, in which form the copper isvery eflective for the purpose and is economical in cost. The coppersulphate applied without lime as a wet spray will injure foliage but isharmless when applied as a powder or dust with lime.

Another objectoi the invention is to pro-' vide'a process of makincommercial arsenate (or arsenite) of lime, which is not only useful asan insecticide hut also for other purposes. I

The principles and steps involved may be briefly stated as follows:

Calcium oxide or stone lime (CaO) has great affinity for water and whenbrought into contact with a solution of arsenic acid in water produces ahydrated Ca(OH) containing a certain pro ortion of arsenate of lime.This action (s acking the lime) generates heat and when copper sulphatecrystals are present or added during the operation oi slacking, theheat, to-

- gether with the aifinity of the lime for water, causes a dehydrationof the copper salt,'the water of the copper sulphate crystals beingtaken up by the slacking lime. It will of course be understood that inthe above process all of the arsenic acid or ar senious acid isneutralized by the lime, and that thelatter is suliiciently in excess tode- Applieation died December 23, 1920.

lime,

Serial No. 43%,632.

hydrate also the copper sulphate crystals which are added. J

The result of the first part of the above operation is the production ofa certain amount of commercial arse-hate of lime,-or calcium arsenate,Ca tAsOfl depending on the amount of arsenic acid used, or if arseniousacid is used calcium arsenite will be produced, in the form of a finepowder,

which is useful as an insecticide and for other purposes.

I have also found that when copper sulphate crystals are ground togetherwith calcium oxide a similar action oi dehydration takes place and adehydrated copper sulphate, in the form of a fine powder, is produced,which is useful as a fungicide, when mixed with lime.

I have found that in place of coppersulphale crystals, copper sulphatein solution may be used. the dehydration of the copper sulphate beingfacilitated by liquid form in its contact with the lime. In this casealso it should be understood that sufficient lime is added to take upall of the water.

In some cases it is desirable to produce a combined insecticide andfungicide in fine powder form and l\ have found that this may beaccomplished by an automatic and continuous process in a simple mannerbyhydrating lime with arsenic (*or arsenious) acid and water, conveyingthe same while hydrating to a mixer into which is simulta-neouslyintroduced dehydrated cop er sulphate formed by mixing, prefera 1y bygrinding together copper sulphate crystals and calcium oxide. Thisproduces a mixture, in fine powder form, ofcommercial arsenate of lime,Ca (AsO,) (or arsenite of lime when arsenious acid is used); hydratedlime, Ca(OH) and dehydrated copper sulphate, CuSO,,; which forms=acombined insecticide and fungicide, the proportionsof each beingdependent upon'th'e amount of water, arsenic acid, 'copper sulphate andlimeused, according to 8% arsenate of lime,- and 77% hydrated lime.

It will be understood that, for the purpose of economy of cost, etc., acommercial copper sulphate is used and the dehydration does notnecessarily consist in the removal of all of the water ofcrystallization, also that other salts may be substituted for thearsenic acid, such as sodium arsenate, calcium arsenate, etc. 7

In fact I contemplate that various changes may be made and othersubstances used according to the principles herein set out withoutdeparting from the spirit and purpose of the invention and it isintended that the particular substances and reactions herein describedshall be considered as illustrative merely of the invention and not inaJiI'niting sense,

What I claim is:

1. The process of producing a mixture in powder form adapted for use asan insecticide and fungicide, which consists'in hydrating calcium oxidewith a solution ofarsenic acid and mixing the same with dehydratedcopper sulphate, the calcium oxide being present in quantity sufiicientto take up all of the free water.

2. The process of producing a mixture in powder formadapted for use asan inmemes secticide and fungicide, which consists in hydrating calciumoxide with a solution of an arsenic compound and mixing the same withdehydrated copper sulphate, the calcium oxide being present in quantity3 sufficient to take up all of the free water,

3. The process of producing a mixturein powder form adapted for use asan'insecticide and fungicide, which consists in hydrating calcium oxidewith a solution of an arsenic compound and simultaneously mixing thesame with copper sulphate, the calcium oxide. being present in quantitysufiicient to take up all of the free water.

. 4. The process of making an insecticide and fungicide, comprising thehydration of calcium oxide with a solution of arsenic acid and addingcopper sulphate thereto while hydrating, the calcium oxide being keptalways in excess to an amount sufiicient to cause a dehydration of thecopper sulphate, producing a mixture in dry powder form containingarsenate of lime and dehydrated copper sulphate,

Signed October 28, 1920.

GEORGE ETHELBERT SANDERS.

